Rock and coal auger



June 30, 1936. R RlcHARDsoN 2,045,725

Fed/n R Pa'cardsaw By @nwo Attorney Patented June 30, 1936 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to new and. improved boring devices and more particularly to an auger especially designed for mining purposes.

An object of the present invention is to provide an auger for drilling coal and rock for providing a bore for the reception of an explosion charge.

At the present time angers of substantially three different diameters are employed with the result that the bored hole for receiving the explosive charge comprises a corresponding number of different diameters. This is undesirable for the reason that in packing the bore or hole with a charge of explosive it is almost impossible to charge the bore back to the closed end of the bore with the powder since at the junction between the two diameters a clogging is likely to and often does result to the end that a premature explosion or blow-out takes place with consequent loss of life and serious injury to the miner.

An object of the present invention is to provide an auger or boring instrument whereby a hole of substantially uniform diameter throughout its length will be provided for receiving the charge of explosive, and wherein further the walls of the bore will be smooth and free of any projection which might result in a choking of the bore and a consequent premature explosion or blowon The invention together with its objects and advantages will be best understood from a study of the following description taken in connection with the accompanying drawing wherein:

Figure 1 is an elevational view of the auger.

Figure 2 is a sectional view taken substantially on the line 2-2 of Figure 1.

Figure 3 is an end view of the auger.

Referring to the drawing by reference numerals it will be seen that the auger includes a shank 5 formed with an integral boring or drilling head indicated generally by the reference numeral 6.

The head 6 is formed by taking a piece of suitable material Y-shaped in cross section and twisting the same by a suitable heating process in any well-known manner so as to provide spiral, (in the present instance, three) blades 1 having concave leading faces 8 and convex following faces 9 merging at the outer edge of the blades into a beveled edge I which at the junction of the face 8 forms a sharp cutting edge ll. Further in constructing the head 6 of the auger the same is tapered longitudinally, decreasing in size progressively from the cutting points l2 of the blades to the shank 5, the largest diameter of the head being thus at the cutting points 12. In this connection it will be noted that at the forward end of the head 6 the blades 1 are beveled to provide the cutting points 12 thus insuring a thorough grinding of the cuttings during the boring operation.

Further by having the head 6 tapered as just described there will be a clearance between the auger and the walls of the bore from the cutting points to the shank end of the auger with the 15 result that the auger is not likely to get stuck within the bore being drilled. Further, with an auger of this character a hole of substantially uniform diameter will be bored, and in actual practice the length of the head 6 will be substantially equal to the length of the hole that is to be bored, preferably nine feet.

Also, due to the spiral twist of the blades and the concave leading faces 8 the cutting will have a tendency to work back lengthwise of the auger and thus prevent sticking and clogging thereby tending to permit smooth performance of the auger in the drilling operation.

Having thus described the invention, what is claimed as new is:

An auger of the character described comprising a shank having integral with one end thereof an elongated boring head substantially Y-shaped in cross section and tapering longitudinally, with its smallest end integral with said shank, said head being helically twisted to provide three spirally twisted blades continuously along said head, each blade being transversely curved to provide a concaved leading face and a convex cutting face, and with the edges of the branches of said Y beveled to provide for each blade at the junction of the convex face and beveled edge thereof a sharpened cutting edge, and said blades at the largest free end of said head being mutually separated and having beveled end edges to pro- Vide at the largest end of the head individual cutting points corresponding in number to the number of said blades.

DEAN ROYDEN RICHARDSON. 

